Wow! Excellent find, Stephen. I also noticed this book (circled in the top left) is actually a real book:
And... while I have not been able to find that same book, "A New History of Erotic Art", I did find this:
The art book might have been a prop., then they would not have to pay for rights etc. that might cost more than having the props. made? Unless it was reissued with a different name?